Idiopathic scoliosis is a disease in which the spin develops a progressive lateral curvature. Its cause is unknown, and if untreated it may result in gross deformity. Approximately one person in five hundred suffers from this disease. The overall purpose of this investigation is (1) to develop better understanding of the mechanical factors involved in the initiation progression of idiopathic scoliosis and (2) to apply this information to improve the methods of evaluation and treatment. Because of the difficulty with the anatomical complexity of the vertebral colum, a basic feature of this program is the use of computer-generated analogs of the spine. Studies of model scoliotic spines will be made in conjunction with clinical studies to provide vital information regarding the three dimensional morphology of the curves, their progression, and their correction. The knowledge gained from these studies will help base treatment on more rational and objective grounds, and the understanding provided may contribute to the discovery of its etiology.